Businesses recognize the commercial value of their data and seek reliable, cost-effective ways to protect the information stored on their computer networks while minimizing impact on productivity. A company might back up critical computing systems such as databases, file servers, web servers, virtual machines, and so on as part of a daily, weekly, or monthly maintenance schedule. The company may similarly protect computing systems used by its employees, such as those used by an accounting department, marketing department, engineering department, and so forth.
File-level data protection using network attached storage (NAS) poses some particular challenges. A number of drawbacks are evident when NAS storage devices, e.g., file servers, filers, etc. interoperate with data storage management systems. When only a few data files are targeted for restoration from a filer-made backup copy that comprises hundreds of thousands or more files, one might expect the restoration to be expeditious since only a few files are to be restored from a very large backup copy. However, some NAS storage devices have inefficient data retrieval strategies that cause the restoration of even a small number of previously backed up files to take unacceptably long. For example, the filer's retrieval procedures may first attempt to reconstruct the hierarchical directory tree of the backed up data before reaching the point where the filer accesses and retrieves the few sought-after files from backup media. In other instances, the filer executes other long-running operations even for a small number of files to restore. These kinds of processes can exceed a reasonable amount of time which is allocated to the restore operation. As a result, users can be left waiting for hours to recover just a handful of files from a very large backup copy. The storage management system that governs the backed up data may time out on the restore job. These undesirable scenarios can undermine the smooth functioning of an otherwise solid data protection strategy.